The invention relates to a frame for a ball game racquet, in particular tennis or squash racquet comprising two hollow profiles and a member held therebetween in which passages are provided through which the guts are to be strung.
It is known to manufacture ball game racquets from a combination of bundles of synthetic fibres together with resins, usually duraplastics based on epoxy resins. The fibres can be embedded in the plastics in the form of fabrics, non-woven sheets or in unidirectional orientation (prepregs), the plastics being present in a so-called B conditions. These prepregs are then further processed to form the desired product in presses or autoclaves, whereby heat and pressure are supplied.
FIG. 1 illustrates a frame profile 1 manufactured in that manner and after a passage has been drilled therethrough. However, that frame 1 cannot be strung without an adaptation of the passages by means of individual eyelets or strips of eyelets 2, being made of soft thermoplastic resins according to FIG. 2, since otherwise the guts would be cut or ripped apart along the edges of the frame 1 bordering the passage.
However, the manufacture and fitting of the individual eyelets or eyelet strips 2 is expensive. In particular the use of eyelet strips presupposes the provision of numerous different eyelet strips adapted to the particular types of racquets, for the manufacture of each eyelet strip a special tool being require.
From U.S. Pat. No. 4,436,307 a tennis racquet has become known, the frame of which is composed of an integral profile in one piece and two hollow profiles interconnected by a central web, the space between the two hollow profiles and the central web being filled by a plastic ribbon connected to the opposite plastic ribbon by webs passing through apertures in the central web. The manufacture of such a frame profile is elaborate and requires the use of inserts. Moreover, apertures have to be drilled through the web interconnecting the two hollow profiles in order to provide the means for connecting the two inserted plastics ribbons. Moreover, the plastic member interconnecting the two hollow profiles must similarly be drilled in order to provide the holes for introducing the guts. Accordingly, two drilling procedures are necessary involving a high degree of manufacturing effort.